Bryophytes and lichens in Latvia were studied already since establishment of the Botanical Garden in 1922 when the director was Nikolay Malta, also world-wide recognized bryologist. At present more than 560 bryophyte species have been recorded in Latvia. Nowadays bryophyte research is carried out in natural habitats like forests, mires and dunes, whereas urbanized environment has been only fragmentary studied. As a result we have little information about bryophytes growing around us in the city on house walls and roofs, tree stems, under drainpipes, in cemeteries, near to railways, in rock gardens etc.

Bryophytes were recently studied at the Botanical Garden and almost 50 species were recorded in the relatively small area suitable fir distribution of many bryophyte and lichen species.

Lichens

Within the lichen thallus, fungi (usually ascomycete rarer basidiomycete or zygomycete), algae and/or cyanobacteria are living in close symbiotic contact. Lichen lack of a waxy cuticle and stomata allows many contaminants to be absorbed over the whole lichen surface. Thus lichens are sensitive against air pollution and have been used as bioindicators very often.